The subject of this article or section is part of Hallow's End, a seasonal event that lasts two weeks. Once the event has run its course, this will no longer be available until next year, but there are no guarantees.
Before patch 4.2.0 it can be obtained from [Treat Bags] by speaking to any innkeeper and selecting the Trick or Treat option.
the Tooth Pick buff in effect
On using the pick, you get a 1 minute buff about your smile. This periodically gives a glinting effect on your character's mouth.
The Hallow's End World Event Achievement, That Sparkling Smile, is completed when you use a Tooth Pick.